Interconnects Are Important, Too: New High-Speed Cabling from TE Connectivity

Harsh environments and high signal frequencies call for cables that can perform reliably under demanding conditions.

I recall a quote—I read this years ago so the details could be way off—to the effect of, “Good generals study tactics, and the best study logistics.” The idea here is that sometimes the less flashy and exciting aspect of an endeavor is actually more important. In the Hollywood world, trucking supplies from here to there isn’t very interesting but, in the real world, the best strategies and battle plans count for nothing if the soldiers are starving to death.

When I think back to my days working in the defense industry, I vaguely recall a similar attitude surrounding the cables and connectors for military systems—“Oh yeah, I’m sure we can find someone to design the PCBs and write the firmware, but who is going to handle the interconnects?” I also remember a particular project for which the connectors had been neglected until somewhat late in the game. I nonchalantly sought assistance from an older engineer and, after some deliberation, we realized that the issue was more complicated and burdensome than expected. Eventually, he says, “No wonder no one spec’d this out yet. . . .”


Image courtesy of TE Connectivity.

It’s certainly true that a 12-layer mixed-signal PCB with blind and buried vias is, overall, more complicated than a system of connectors and cables. But it is also true that it is possible for a project to go very wrong as a result of interconnect issues.
  • Can the cables handle the signal frequencies involved?
  • Is there an engineer in the building who really understands what a ground loop is? And if so, could he or she please look at this cabling diagram?
  • Is the shielding adequate for the expected noise levels? Do we need twisted-pair?
  • Are there mechanical or environmental concerns—abrasion, excessive bending, high temperatures, shock, vibration?
  • Has anyone double-checked the pinouts?
  • Do the connectors need to be keyed—i.e., must it be physically impossible to make an improper connection?
  • Can the contacts in the power-supply connector handle the expected current?
  • Do we have the tooling needed to assemble these things? How many different crimp tools will we need to buy?
I could probably think of a few more bullet points, but you get the idea. In some ways, these issues are more evasive—or at least more easily ignored—than the challenges and pitfalls involved in schematic design and PCB layout.

IEEE 1394

In this article, we’ll take a look at a TE Connectivity cable that is specifically designed for military and aerospace environments. It’s described as an “IEEE 1394” cable. This might seem slightly confusing at first because IEEE 1394 is associated with FireWire, which is a serial communication bus used with consumer electronics.


The FireWire logo.

We generally don’t expect to see consumer-electronics protocols or devices in, say, a jet fighter.
The issue here is that IEEE 1394 is not limited to FireWire and there is nothing inherent in the protocol that makes it inappropriate for use in military or aerospace systems. In fact, there is a specific SAE standard (it goes by the name of AS5643) that describes the “requirements for the use of IEEE-1394b . . . in military and aerospace vehicles.” This product-description document (it’s not a datasheet and I’m not sure what to call it) lists AS5643 under the “Standards and Specifications” heading and, presumably, this means that the cable is somehow in accordance with requirements set forth in the SAE document.

Features

As you can see in the following diagram, cables these days are not as simple as we might expect.


Diagram courtesy of TE Connectivity.

One thing I appreciate about this cable is the clear and highly informative datasheet. It provides specs for impedance, crosstalk, capacitance, time delay, time delay skew between pairs, and velocity of propagation. It seems to me that these details would be helpful if you wanted to use this cable with a high-speed protocol other than IEEE 1394, assuming that you can find someone who is able to intelligently interpret this data with respect to the protocol’s signaling characteristics.
However, if you just need a rough idea of this cable’s high-frequency performance, you know that it is adequate for IEEE 1394b and this, in turn, means that it can handle serial data rates up to 3.2 Gbps.




Do you have any experience with IEEE 1394 in a harsh environment or high-reliability application? Let us know in the comments.
Previous
Next Post »
My photo

Hi, I`m Sostenes, Electrical Technician and PLC`S Programmer.
Everyday I`m exploring the world of Electrical to find better solution for Automation. I believe everyday can become a Electrician with the right learning materials.
My goal with BLOG is to help you learn Electrical.
Related Posts Plugin for WordPress, Blogger...

Label

KITAIFA NEWS KIMATAIFA MICHEZO BURUDANI SIASA TECHNICAL ARTICLES f HAPA KAZI TU. LEKULE TV EDITORIALS ARTICLES DC DIGITAL ROBOTICS SEMICONDUCTORS MAKALA GENERATOR GALLERY AC EXPERIMENTS MANUFACTURING-ENGINEERING MAGAZETI REFERENCE IOT FUNDAMENTAL OF ELECTRICITY ELECTRONICS ELECTRICAL ENGINEER MEASUREMENT VIDEO ZANZIBAR YETU TRANSDUCER & SENSOR MITINDO ARDUINO RENEWABLE ENERGY AUTOMOBILE SYNCHRONOUS GENERATOR ELECTRICAL DISTRIBUTION CABLES DIGITAL ELECTRONICS AUTOMOTIVE PROTECTION SOLAR TEARDOWN DIODE AND CIRCUITS BASIC ELECTRICAL ELECTRONICS MOTOR SWITCHES CIRCUIT BREAKERS MICROCONTROLLER CIRCUITS THEORY PANEL BUILDING ELECTRONICS DEVICES MIRACLES SWITCHGEAR ANALOG MOBILE DEVICES CAMERA TECHNOLOGY GENERATION WEARABLES BATTERIES COMMUNICATION FREE CIRCUITS INDUSTRIAL AUTOMATION SPECIAL MACHINES ELECTRICAL SAFETY ENERGY EFFIDIENCY-BUILDING DRONE NUCLEAR ENERGY CONTROL SYSTEM FILTER`S SMATRPHONE BIOGAS POWER TANZIA BELT CONVEYOR MATERIAL HANDLING RELAY ELECTRICAL INSTRUMENTS PLC`S TRANSFORMER AC CIRCUITS CIRCUIT SCHEMATIC SYMBOLS DDISCRETE SEMICONDUCTOR CIRCUITS WIND POWER C.B DEVICES DC CIRCUITS DIODES AND RECTIFIERS FUSE SPECIAL TRANSFORMER THERMAL POWER PLANT cartoon CELL CHEMISTRY EARTHING SYSTEM ELECTRIC LAMP ENERGY SOURCE FUNDAMENTAL OF ELECTRICITY 2 BIPOLAR JUNCTION TRANSISTOR 555 TIMER CIRCUITS AUTOCAD C PROGRAMMING HYDRO POWER LOGIC GATES OPERATIONAL AMPLIFIER`S SOLID-STATE DEVICE THEORRY DEFECE & MILITARY FLUORESCENT LAMP HOME AUTOMATION INDUSTRIAL ROBOTICS ANDROID COMPUTER ELECTRICAL DRIVES GROUNDING SYSTEM BLUETOOTH CALCULUS REFERENCE DC METERING CIRCUITS DC NETWORK ANALYSIS ELECTRICAL SAFETY TIPS ELECTRICIAN SCHOOL ELECTRON TUBES FUNDAMENTAL OF ELECTRICITY 1 INDUCTION MACHINES INSULATIONS ALGEBRA REFERENCE HMI[Human Interface Machines] INDUCTION MOTOR KARNAUGH MAPPING USEUL EQUIATIONS AND CONVERSION FACTOR ANALOG INTEGRATED CIRCUITS BASIC CONCEPTS AND TEST EQUIPMENTS DIGITAL COMMUNICATION DIGITAL-ANALOG CONVERSION ELECTRICAL SOFTWARE GAS TURBINE ILLUMINATION OHM`S LAW POWER ELECTRONICS THYRISTOR USB AUDIO BOOLEAN ALGEBRA DIGITAL INTEGRATED CIRCUITS FUNDAMENTAL OF ELECTRICITY 3 PHYSICS OF CONDUCTORS AND INSULATORS SPECIAL MOTOR STEAM POWER PLANTS TESTING TRANSMISION LINE C-BISCUIT CAPACITORS COMBINATION LOGIC FUNCTION COMPLEX NUMBERS ELECTRICAL LAWS HMI[HUMANI INTERFACE MACHINES INVERTER LADDER DIAGRAM MULTIVIBRATORS RC AND L/R TIME CONSTANTS SCADA SERIES AND PARALLEL CIRCUITS USING THE SPICE CIRCUIT SIMULATION PROGRAM AMPLIFIERS AND ACTIVE DEVICES BASIC CONCEPTS OF ELECTRICITY CONDUCTOR AND INSULATORS TABLES CONDUITS FITTING AND SUPPORTS CONTROL MOTION ELECTRICAL INSTRUMENTATION SIGNALS ELECTRICAL TOOLS INDUCTORS LiDAR MAGNETISM AND ELECTROMAGNETISM PLYPHASE AC CIRCUITS RECLOSER SAFE LIVING WITH GAS AND LPG SAFETY CLOTHING STEPPER MOTOR SYNCHRONOUS MOTOR AC METRING CIRCUITS APPS & SOFTWARE BASIC AC THEORY BECOME AN ELECTRICIAN BINARY ARITHMETIC BUSHING DIGITAL STORAGE MEMROY ELECTRICIAN JOBS HEAT ENGINES HOME THEATER INPECTIONS LIGHT SABER MOSFET NUMERATION SYSTEM POWER FACTORS REACTANCE AND IMPEDANCE INDUCTIVE RESONANCE SCIENTIFIC NOTATION AND METRIC PREFIXES SULFURIC ACID TROUBLESHOOTING TROUBLESHOOTING-THEORY & PRACTICE 12C BUS APPLE BATTERIES AND POWER SYSTEMS ELECTROMECHANICAL RELAYS ENERGY EFFICIENCY-LIGHT INDUSTRIAL SAFETY EQUIPMENTS MEGGER MXED-FREQUENCY AC SIGNALS PRINCIPLE OF DIGITAL COMPUTING QUESTIONS REACTANCE AND IMPEDANCE-CAPATIVE RECTIFIER AND CONVERTERS SEQUENTIAL CIRCUITS SERRIES-PARALLEL COMBINATION CIRCUITS SHIFT REGISTERS BUILDING SERVICES COMPRESSOR CRANES DC MOTOR DRIVES DIVIDER CIRCUIT AND KIRCHHOFF`S LAW ELECTRICAL DISTRIBUTION EQUIPMENTS 1 ELECTRICAL DISTRIBUTION EQUIPMENTS B ELECTRICAL TOOL KIT ELECTRICIAN JOB DESCRIPTION LAPTOP THERMOCOUPLE TRIGONOMENTRY REFERENCE UART WIRELESS BIOMASS CONTACTOR ELECTRIC ILLUMINATION ELECTRICAL SAFETY TRAINING FILTER DESIGN HARDWARE INDUSTRIAL DRIVES JUNCTION FIELD-EFFECT TRANSISTORS NASA NUCLEAR POWER SCIENCE VALVE WWE oscilloscope 3D TECHNOLOGIES COLOR CODES ELECTRIC TRACTION FEATURED FLEXIBLE ELECTRONICS FLUKE GEARMOTORS INTRODUCTION LASSER MATERIAL PID PUMP SEAL ELECTRICIAN CAREER ELECTRICITY SUPPLY AND DISTRIBUTION MUSIC NEUTRAL PERIODIC TABLES OF THE ELEMENTS POLYPHASE AC CIRCUITS PROJECTS REATORS SATELLITE STAR DELTA VIBRATION WATERPROOF